"Porous Silicon Photonics Crystals for Templating and Drug Delivery"

Friday, October 29, 2004

Yang Yang Li

Materials Science and Engineering, University of California, San Diego

Abstract:  Elaborate one-dimensional photonic crystals are constructed by  electrochemically etching pores in a silicon wafer.  The spectral features of the photonic crystals derive from a porosity gradient that is determined by the electrochemical etching parameters.  It is shown that the spectral properties of the porous Si photonic crystal can be transferred to a variety of organic and bio-polymers by templating on porous silicon multilayer (rugate dielectric mirror) structures. After the removal of the template by chemical dissolution, the polymer castings replicate the photonic features and the nanostructure of the master. We demonstrate that these castings can be used as vapor sensors, as deformable and tunable optical filters, and as self-reporting, bioresorbable materials.